Thats not hugely important, github has at least an email for targeted accounts.

Its not really reasonable to expect a copyright holder to have anything more than the github account/repo as everything else can be kept private.

Radicle is a decentralized tool built on top of Git. There’s also ForgeFed which is being integrated into Forgejo.

Suyu hosts a full backup of Yuzu (and other stuff like Ryujinx or Dolphin in case it gets taken down at some point) on their Forgejo instance

It’s also available via Tor as an onion site: http://suyudev2qxj5x7mroamgwf4hqunz4pups27z2kl77x4ioqhh5yhpshad.onion/

Plenty on web archive or peer to peer. Or use Ryujinx :)